1. Field of the Invention
This invention relates to a heating element temperature estimation apparatus, particularly to an apparatus for estimating a temperature of a heating element such as a power semiconductor device like a MOSFET, mounted on an electronic printed circuit board and having heat generating property.
2. Description of the Related Art
Conventionally, there is proposed a technique for estimating temperature of a heating element so as to estimate its duration of life from the estimated temperature, as taught, for example, by Japanese Laid-Open Patent Application No. 2006-114575, in which two diodes are separately installed at the heating element to detect a temperature difference therebetween. Specifically, a difference between voltages at which diodes become conductive is used as the temperature difference and the duration of life of the heating element is estimated by comparing the detected temperature difference with a reference value.